Update mypy.ini from skeleton

mypy.ini

@@ -1,12 +1,26 @@
 [mypy]
-# CI should test for all versions, local development gets hints for oldest supported
-# But our testing setup doesn't allow passing CLI arguments, so local devs have to set this manually.
-# python_version = 3.8
+## upstream
+
+# Is the project well-typed?
 strict = False
+
+# Early opt-in even when strict = False
 warn_unused_ignores = True
 warn_redundant_casts = True
-# required to support namespace packages: https://github.com/python/mypy/issues/14057
+enable_error_code = ignore-without-code
+
+# Support namespace packages per https://github.com/python/mypy/issues/14057
 explicit_package_bases = True
+
+# Disable overload-overlap due to many false-positives
+disable_error_code = overload-overlap
+
+## local
+
+# CI should test for all versions, local development gets hints for oldest supported
+# But our testing setup doesn't allow passing CLI arguments, so local devs have to set this manually.
+# python_version = 3.8
+
 exclude = (?x)(
 	# Avoid scanning Python files in generated folders
 	^build/
@@ -19,8 +33,6 @@ exclude = (?x)(
 	# Duplicate module name
 	| ^pkg_resources/tests/data/my-test-package-source/setup.py$
 	)
-# Too many false-positives
-disable_error_code = overload-overlap
 
 # DistributionMetadata.license_files and DistributionMetadata.license_file
 # are dynamically patched in setuptools/_core_metadata.py